“The Impossible” is the story of the unthinkable: a December 2004 earthquake under the Indian Ocean, whose subsequent tsunami waves killed hundreds of thousands of people in 11 countries. The film, directed by J.A. Bayona (“Orphanage”), makes it clear from the beginning that it is not the story of any of those people, but is instead a tale of survival; specifically, of a handsome British family vacationing in Thailand for Christmas. The parents, played by Naomi Watts and Ewan McGregor, are successful professionals; the three young sons are charming and happy — until a massive wave crashes into the posh resort where they’re staying, dividing the family and resulting in several days of agony before they can be reunited again.

Filmed with urgency and remarkably realistic special effects, “The Impossible” moves breathlessly through its story. Maria (Watts) and her oldest son Lucas (Tom Holland) are separated from the other three by the wave’s force; she’s badly injured, and young Lucas must become heroic as he helps his dazed yet fiercely protective mother find help (and rescues another child along the way). Watts lets us feel Maria’s excruciating pain, both physical and emotional, as she faces the very real possibility that her husband and other two sons may be dead; Holland, a very talented child actor, shows us Lucas’ not-quite-hidden panic, which becomes worse when he is separated from his mother at a crowded hospital. Husband Henry (McGregor) and the other children have less screen time but are equally affecting, as the dirty brown water strewn with dead fish and dead humans swirls around them; their vacation paradise quickly turned watery hell.

Though the real-life drama is undeniably moving, it’s hard to watch “The Impossible” without squirming at its strange imbalance: At its heart, the movie is about a family who had a very, very bad vacation, and pays little attention to the many thousands of people whose fate was far worse. You watch wondering where all the Thai people are, and why this movie leaves the odd impression that wealthy tourists were the most affected by the tragedy. It’s a beautifully acted and impressively realized film — but ultimately “The Impossible” feels like the wrong story, well told.

Moira Macdonald: mmacdonald@seattletimes.com. Moira Macdonald is the movie critic at The Seattle Times, where she also regularly weighs in on her other favorite things: ballet, books, “Mad Men,” and shoes.